Senate Democrats contend they found a loophole that allows them vote on bills: A Republican senator unknowingly walked through the back of the chamber this afternoon when Democrats were convening their own session.

Sen. Frank Padavan, R-Queens, acknowledged that he walked through the chamber, but denied that he did so during the session.

“I was not there when the session began. I was in the lounge,” he said. “I think it’s fraud.”

But that didn’t stop Democrats, who have been locked in a 31-31 vote stalemate for three weeks, to take control of the chamber and start passing dozens of bills that have been held up in the leadership fight.

Then Democrats held a Senate Rules Committee meeting in the back of the chamber to begin adopting another series of bills, including sales-tax extenders for local governments.

They claim that since Padavan walked through the chamber, even if it was before the session, he legally indicated that he was present for session and could be counted as voting in favor of bills. That would give them the 32 votes needed to pass legislation.

“Senator Padavan gave us the 32 votes, and he deserves credit for that,” said Sen. Diane Savino, D-Staten Island.

Whether the Democratic session is legal will certainly be disputed. Gov. David Paterson, who was holding a news conference downstairs in the Capitol when the commotion was under way in the Senate chambers, initially said he would sign the bills if Padavan had agreed to vote on the bills. But then he got a telephone call from Padavan during the news conference and left.

He returned to say that Padavan told him that he walked through the chamber before the session. Paterson then said he wouldn’t sign any bills passed during the Democratic session.

“I will take his word for that,” Paterson said. He called another special session of the Senate for 7 p.m. tonight.

Here’s Paterson talking about the Padavan issue, courtesy of video from Senate Republicans.